GE AKTA avant, User Manual

Page: 403 / 538

Air segment test
As shown in the previous pressure curves, very often malfunction in inlet or outlet check
valves gives the same increased pressure curve pulsation. Sometimes the "air segment
test" can help determine if the problem is on the inlet side or the outlet side.
• Introduce an air segment in the inlet tubing while the pump is working.
•
Check how the segment moves towards the pump. If the inlet check valves are
working properly the air segment will not show any backward movement. If it does,
the problem is on the inlet check valve side.
Remove persistent air bubbles
After purging the pump (see Section 5.4.1 Prime buffer inlets and purge system pumps,
on page 166), check that all air bubbles have been removed by analyzing the precolumn
pressure curve (see examples above). If the pressure curve indicates that there are still
air bubbles present, repeat the purging process. If the problem persists, follow the in-
structions below to purge the pump with methanol (see Section 5.4.1 Prime buffer inlets
and purge system pumps, on page 166 for detailed instructions for the purge procedure).
1 Make sure that the pump contains water.
2
Use a syringe to draw 100% methanol into the pump (see Section 5.4.1 Prime buffer
inlets and purge system pumps, on page 166 for details).
3 Set the pump flow to 2.5 ml/min for ÄKTA avant 25 or 10 ml/min for ÄKTA avant 150.
4 Let the flow run until the disturbances in the pressure curve disappear.
5
Remove the methanol:
•
Stop the pump and move the inlet tubing to water. Make sure that no air is intro-
duced into the system.
• Set the pump flow to 1 ml/min for ÄKTA avant 25 or 5 ml/min for ÄKTA avant
150.
• Run for 5 minutes.
6 Purge the pump again using an appropriate buffer.
ÄKTA avant User Manual 29035184 AE 403
8 Troubleshooting
8.6 Troubleshooting: Pumps